api: Fix internal log macros to allow use of U suffix in LOG_LEVEL_N.
api: Fix internal log macros to allow use of U suffix in LOG_LEVEL_N.

Internal macros like _LOG_XXXX0 use preprocessor ## and LOG_LEVEL_N
to conditionally generate code.
After addition of U suffixes to LOG_LEVEL_N macros the internal macros
also need update to versions with suffix i.e. _LOG_XXXX0U

Signed-off-by: Artur Lipowski <8a689fe02400efda4acbcab18a319f0fd3d99665@hidglobal.com>

galak/zephyr,galak/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,Vudentz/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,Vudentz/zephyr,nashif/zephyr,nashif/zephyr,Vudentz/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,Vudentz/zephyr